Number of solutions to 1^4*k_1 + 2^4*k_2 + ... + n^4*k_n = 1, where k_i are from {-1,0,1}, i=1..n.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =1a(9) =2a(10) =5a(11) =13a(12) =25a(13) =56a(14) =110a(15) =218a(16) =494a(17) =1216a(18) =2702a(19) =6477a(20) =14752a(21) =35758a(22) =83730a(23) =208107a(24) =499459a(25) =1250815a(26) =3048590a(27) =7787399a(28) =19260830a(29) =49686365